1. Field of the Invention
The present invention relates to a pressure loss analysis method, a program for executing the pressure loss analysis method, and a pressure loss analysis apparatus.
2. Description of the Related Art
Honeycomb structures including partition walls that form a plurality of cells serving as flow paths for a fluid are known so far (for example, PTL 1). Honeycomb structures are used to clean exhaust gas from internal combustion engines, for example, automobile engines, and prediction of a pressure loss that occurs when exhaust gas passes through a honeycomb structure is carried out. In PTL 1 for example, a pressure loss is predicted by virtually separating the factors that cause the pressure loss in a honeycomb structure into four kinds of factors on the basis of an internal pressure distribution determined using computational fluid analysis and by adding the values of the pressure loss predicted for the four kinds of factors together. PTL 1 states that a pressure loss can be accurately predicted in this way.
PTL 1 gives an example of a pressure loss prediction method for a catalytic converter that converts harmful substances in gas to harmless substances by just allowing the gas to pass through open flow paths of cells of a honeycomb structure to bring the gas into contact with a catalyst that coats the surfaces of the cell partition walls. Other exemplary usages of a honeycomb structure include the use of a honeycomb structure in which inlets and outlets of cells are alternately plugged such that gas passes through cell partition walls in order to filter particulate matter contained in engine emissions and exhaust gas from other combustion devices and the use of such a structure in order to filter solid particulates contained in a liquid, such as water. In this filtering usage, pressure loss prediction in a state where particulate matter has accumulated is essential because resistance of each partition wall against the passing gas increases due to accumulation of particulate matter on the partition wall. In conventional pressure loss prediction methods for the particulate matter accumulation state, the analysis is performed on the assumption that particulate matter accumulates on the surfaces of the partition walls in a uniform thickness t (t=M/S, where M denotes the total amount of particulate matter and S denotes the total surface area of partition walls of inlet cells) as in NPL 1, for example.